Cetology

Cetology is a branch of marine mammal science that studies about eighty species of dolphins, whales, and porpoise, all of which are classified within the Cetacea order. Cetologists, who practice cetology, work to understand the distribution, development, behavior, and other aspects of cetaceans.

The study of cetaceans began in the Classical era. About 2,300 years ago, Aristotle documented details about some cetacean species, calling them mammals, while traveling on the Aegean Sea with fisherman. He distinguished between toothed whales and baleen whales in his book Historia animalium and also described details about the common dolphin and sperm whales. His distinctions between certain types of whales are stilled used in taxonomy today, and his findings about the lifespan of different species are still considered remarkable. There are many medieval texts, mostly from Iceland Scandinavia, that were written in the 13th century that describe cetaceans, including the well-known Speculum Regale. It notes a species called orcs, now known as orcas, which have sharp teeth like those of dogs and attack other cetaceans in packs like dogs. Whalers documented most of the information about cetaceans between the 16th and 20th centuries, but this information rarely included anything other than migration routes and external anatomy.

Identifying cetaceans, especially in recent years, has helped experts understand social structures and population numbers of many species. Photo identification has become one of the most popular means of identifying cetaceans. Michael Bigg and Graeme Ellis pioneered modern orca research in the 1970’s. After taking photos of orcas residing in the British Columbian seas, they examined the photos and noticed that individuals could be identified by noting certain physical characteristics like the shape of the saddle patch and the condition of the dorsal fin. These characteristics were found to be as distinct and different as human fingerprints, and they found that the individuals travel in groups called pods. These photo studies have been used to identify humpback whales, which have differing flukes and pectoral fins.

Despite advances in technology, cetology can be a difficult science. Many species spend only about ten percent of their waking time at the surface of the water, and this is only to breath. Unlike land mammals, cetaceans do not leave indications that they have been at the surface, although their feces sometimes floats and can be used to study the diet of the species. Many times cetologists must spend long periods of time waiting, using tools like hydrophones to listen to the sounds of species as well as optical devices like binoculars to locate surfacing individuals. One method that alleviates waiting involves studying the carcasses of dead cetaceans, which can provide information that cannot be obtained in field studies.

Image Caption: Bottlenose Dolphin – Tursiops truncatus, A dolphin surfs the wake of a research boat on the Banana River. Credit: NASA/Wikipedia